Rose D'souza, Columbia University Graduate School of Journalism, Class of 2012

Data Visualization and The Guardian

I can’t knock the Guardian, I know the paper is leading the way for technological innovation in journalism. The iPhone app is neat and interactive and the paper is now known for its work in data journalism.

It’s supposed to be a visualization of the gender gap in salaries based on information provided by the Annual Survey of Hours and Earnings from the Office of National Statistics in the UK. I want to like it because, if you know me by now, gender inequality is my “issue”.

Yet I can’t understand why the Guardian created this interactive visualization because I think the salaries comparison by profession make little sense. For example, if you search “pharmacy managers”, you will find that the median salary for men is £49,865 and for women is £32,688. So the gender gap for pharmacy managers’ salary is 34.2% – women make 34.2% less than what men make as pharmacy managers.

But this data set doesn’t seem to consider other variables, such as whether male pharmacy managers have a higher income because they tend to be in more senior positions than their female colleagues. And what if the number of female pharmacy managers is significantly less than male pharmacy managers? The median would be skewed if the women’s salaries were very different.

The data visualization, in general, also makes a broad comparison of professions without considering salary differences in the private and public sector, and if people receive a higher income because they have more experience. The Guardian only states that the “chart shows median salaries for full-time employees on adult rates who have been in the same job for more than a year.” We know nothing more about the quality of the data.